A data accessing system usually comprises a data access unit and a data storage unit. The data access unit is a processor or a peripheral. The data storage unit is a storage device, such as a hard disk drive (HDD), solid state disk (SSD), or other device for storing data.
When the data access unit is configured to access data in the data storage unit, the data access unit issues one or more request instructions to the data storage unit. The data storage unit receives and executes the one or more request instructions to access data. For example, data can be written into the data storage unit from a memory or read from the data storage unit to the memory. After accessing data, the data storage unit transmits one or more response instructions to the data access unit for replying that the data access has been completed.
If the data access unit is configured to access a plurality of datasets with continuous addresses, the plurality of request instructions can be combined into a request instruction. The data storage unit receives the request instruction and access the plurality of datasets. If the addresses of the plurality of datasets are not continuous, the request instructions can not be combined into a request instruction, the data access unit and the data storage unit can only complete the data access of the plurality of datasets one by one.
Please refer to FIG. 1. The data access unit is configured to access (read or write) the three datasets D1, D2, and D3. Since the addresses of the three datasets D1, D2, and D3 are continuous, the data access unit combines the request instructions into a request instruction and assigns the address (Address 1) of dataset D1 as the address of the request instruction. The data storage unit 15 receives the request instruction and accesses the three datasets D1, D2, and D3 with continuous addresses according to Address 1. In another case, the data access unit is configured to access the three datasets D4, D5, and D6. Since the addresses (Address 4-6) of the three datasets D4, D5, and D6 are not continuous, the request instructions can not be combined into a request instruction. The data access unit transmits the request instruction of dataset D4 to the data storage unit 15. After the data storage unit 15 completes the data access of dataset D4, it transmits a response instruction to the data access unit. The data access unit can not access dataset D5 (and dataset D6) until it receives the response instruction corresponding to the data access of dataset D4. For accessing a plurality of datasets with discrete addresses in the prior art, the data access processes are executed one by one, it is not efficient and cost a lot of time.